1. Technical Field
The present disclosure relates to a method of manufacturing a mask and, more particularly, to a method of manufacturing a mask for forming a pattern on a wafer using a self-aligning double patterning process.
2. Description of the Related Art
The speed of the reduction of a design rule has increased at a faster pace than the speed of the development of exposure equipment. Accordingly, research into methods for realizing a pitch less than the minimum pitch that can be realized using exposure equipment is currently being conducted. Of the methods, the most representative is a Self-Aligning Double Patterning (SADP) process.
A description of the SADP process is given below. First, a mask data pattern is designed using a first pitch which can be realized using exposure equipment, and a first hard mask layer pattern is formed on a wafer using a mask layer that corresponds to the mask data pattern. Thereafter, a sacrificial layer and a second hard mask layer are formed on the first hard mask layer pattern, and a hard mask layer pattern having a second pitch less than the first pitch is formed using a planarization process and an anisotropic etching process. Using the above-described method, a pitch, which is less than the minimum pitch that can be realized using exposure equipment, is realized, so that fine patterns that help realize high integration can be formed.